Vane pumps



Jan. 8, 1963 G. WEISS 3,072,068

VANE PUMPS Filed Oct. 13, 1958 2 Sheets-Sheet 1 WWW 17777770 A INVENTORGERHART WEISS ATTORNEY Jan. 8, 1963 G WEISS 3,072,068

VANE PUMPS Filed Oct. 13, 1958 2 Sheets-Sheet 2 FIG. I2.

FIG. I6.

INVENTOR GERHART WEISS ATTORNEY ilnire This invention relates to rotarypumps especially suited to feed air, gas, fuel vapors, liquids orexhaust mixtures to or from catalytic elements, respectively.

One of the objects of the invention is to provide a gas pump of therotary type of simple and rugged construction capable of operating atreltively elevated temperatures with a high degree of efficiency.

Another object of the invention is to reduce friction to a minimumwithout any lubrication and without substantial wear and other losses,and more specifically, to eliminate oil from the pump entering into anyof the following lines or parts of the equipment.

A more specific object of the invention is to provide a rotary pumpconsisting of a stationary outer casing and an eccentrically rotatableinner casing or rotor mounted thereon rotatable and coaxial with theouter casing and an impeller having at least one vane extending from itsaxis to a distance very close to but not in contact with I the outercasing.

Another object of the invention is to provide in an eccentrical rotor aradial vane rotating under control of the rotor in a peripheral openingof the rotor but having at its inner end stopping means preventingcontact with the outer casing.

Still another object of the invention is to provide one or more radialvanes forming an impeller supported rotatable about an axis coaxial withthe casing in an eccentrical pump rotor, said vanes being slidablysupported in guide slots provided along the periphery of the rotor andequipped with friction reducing fittings or coatings such as nylon orTeflon layers or the like.

Alternatively, the edges of the guide slots are made of hard materialsuch as chrome-plated steel while the vanes are made of relatively softmaterial such as laminated plastic, perferably containing graphite orother friction-reducing particles.

According to an additional object of the invention the outer casing of aguided vane pump consists of diecast material with a cylindrical boreand a cover disc attached thereto, the cylindrical bore having an axialprojection forming a bearing for the impeller, the rotor consistingsubstantially of another single diecasting, which is rotatable andsupported eccentrically on the cover, having peripheral slots slidinglysupporting one or more radial impeller vanes extending therefrom to apredetermined distance from the inner wall of the cylindrical bore.

Alternatively, the axial projection supporting the impeller may beprovided on the cover disc, the rotor being supported eccentricallyrotatable on the casing.

Still another object of the invention is to provide the impeller vaneswith a rotatable support flexibly on a common shaft so that the vanesmay rotate freely relative to each other under control of the rotormovements.

These and any other objects of the invention will be more fully apparentfrom the drawings annexed herewith in which FIGS. 1 and 2 represent infront and side elevations, respectively, and partly in section, a pumpvane embodying certain features of the invention.

FIG. 3 represents a modification of the impeller as shown in FIG. 2.

FIG. 4 represents the corresponding rotor in top view and FIG, 5, amodification of FIG. 4.

aent I Patented Jan. 8, 1963 ice FIG. 6 represents the vane slidingarrangement of FIG. 4 in cross section.

FIG. 7 represents a modified vane sliding arrangement, and FIG. 8,another modification of such an arrangement.

FIGS. 9 and 10 represent modifications of a rotor and stator,respectively, such as shown in FIGS. 1, 2, 3, and 4.

FIG. 11 represents in cross section another fuel pump with a modifiedvane support.

FIG. 12 represents diagrammatically a pump including another vanesupport also coupled to the rotor.

PEG. 13 represents a perspective view of a portion of the arrangementshown in FIG. 12.

FIGS. 14 and 15, in front and top elevations, respectively, the formerin cross section, show another vane support.

FIG. 16 represents another sealing mechanism for the vanes and FIG. 17,a modification of FIG. 16 in a perspective view.

In FIGS. 1 and 2, the stationary housing or stator 1 of a rotary vanepump is provided with a ring-shaped rotor 2 which is rotatably mountedeccentrically with respect to stator 1, on one side thereof, on a shaft3 and bearing 4, and on the other side thereof, in an annular groove 5.The parallel end surfaces of rotor 2 are in contact with annular feltrings 2. A similar strip 2", made of felt or of resilient low frictionmaterial, may be provided at the near contact point of casing bore 6 androtor 2.

The annular felt rings 2, being impregnated with graphite or molybdenumdisulfide containing grease or silicon lubricant and the like, form aleakage seal.

Stator 1 is provided with a cylindrical bore 6 into which extendsaxially a shaft '7, integrally connected with or attached to cover plate1' of stator l, and supported rotatably thereon on hubs 3, 9, and 10,are vanes 11, 12, and 13, respectively.

Vanes 11, t2, and 13 extend into bore 6 through longitudinal slots 14,id, and to of rotor 2 between semicircular sliding rods 1! which arerotatably mounted in slots 14, 15, and Hand which slide radially onvanes 11, 12, and 13 causing rods 17 to rotate about their common axisin accordance with the relative movement between vanes 11, 12, 13 androtor 2.

In accordance with a specific feature of the invention, vanes 11, 12,and 13 are not arranged in frictional engagement with the wall ofcylindrical bore 6 but have a clearance of, say, five thousandths of aninch from said wall which has been found sufficient to assure eflicientoperation of the pump mechanism.

Inlet and outlet openings are provided in stator l at its and 19:,respectively, in otherwise Well known manner.

In this way with a minimum wear and frictional loss, high etliciency ofoperation is assured.

At the same time, friction members 17 can be made in an extremely simplemanner, easily exchangeable and provided with low friction surfaces forexample in the form of nylon rods or grease-impregnated felt insertsshaped to conform with the semicircular configuration required of parts17 or any other form.

Alternatively, rods 17 may be replaced by steel, carbon, glass, or otherWear-resistant material while vanes 11, i2, 1'3 may be made ofrelatively soft material such as phenolic plastic, or conversely.

As apparent from FIGS. 1 and 4, slots 14, 15, 16 in rotor 2 are closedat both ends thereof to assure relative position and predeterminedmotion of members 17 under control of the movement of vanes ill, 12, 13relative to rotor 2.

aoraoee In another modification shown in FIG. 5, the slots in rotor Zare closed at one end only and open at the other end as indicated inFIG. at 20.

In this case, the sliding members are not arranged rotatable but firmlyattached to the side walls of the slots in a manner such as shown, forexample, in FIG. 6 where cylindrical low-friction rods 21, 22 arefixedly inserted into the walls of a slot 23 in a rotor body 24 with thevane 25 being arranged slidingly therebetween.

In another modification shown in FIG. 7, rotor body 26 has slots 2'7,one wall of which has attached thereto at 23 a low-friction member ofsemicircular shape, and the other wall of which has attached thereto aflexible pressure member as, for example, indicated at 29 and providedwith a low-friction nylon coating as indicated at 30 with vane 31 beingarranged therebetween.

With rotor 26 rotating in the direction shown at 32, the main frictionload will be carried by low-friction edge 28 while pressure member 2?merely serves to define the position of vane 31 in its rest position orat speed change, or to take up any wear of edge 28.

In the modification shown in FIG. 3, the number of vanes is increased tosix to reduce wear on the individual vanes and also to increase thenoise frequency which is more easily muffled.

At the same time, each vane 4i) is supported, not on rings sliding onshaft 7, as shown in H6. 2, but molded into elastic body 42, hearingridges 41, which is attached to, pressed on, or molded over shaft 7.

Body 42 is made of rubber or other elastic but longwearing material topermit oscillatory movement of blades in corresponding slots (not shown)of an eccentric rotor such as shown in FIG. 3 at 43 but otherwiseconstructed in a manner similar to that shown in FIG. 1 at 2.

In this embodiment, the inner space of casing 1 has two part-cylindricalportions. The axes of shaft 7 and Said part-cylindrical portion areco-incident. The axis of cylindrical rotor 4-3 is offset with respect toand parallel to the (longitudinal) axis of shaft 7. The six axial slotsof rotor 43 extend in the direction of length thereof and are equallycircumterentially spaced. Body 42 serves as an elastomer hub fixedlymounted upon shaft 7. The ridges 41 are projections unitary and integralwith hub 42 and are equally circumferentially spaced, circumferentiallyflexible and resilient. Projections 41 are in respective generalcorrespondence with respective rotor slots and are located radiallyinwardly of rotor 43.

The vanes as are respectively imbedded in the respective hub projections41 and extend approximately to the inner ends thereof. Vanes 40 extendgenerally radially from hub 42 and also extend longitudinally. Vanes 40are of length corresponding to the axial length of the rotor slots. Hub42 and projections 41 are generally of the same length as vanes iii.

Vanes 4i respectively extend slidably through the respective rotorslots. The tips of vanes at) are located in a cylinder of revolutionwhose axis is co-incident with the axis of shaft 7. Eachpart-cylindrical casing portion has a radius such as to receive the tipsof the rotating vanes 40 in close, generally uniformly spacedrelationship to said part-cylindrical wall portions.

The smaller angle (between adjacent vanes 4%), being 60 plus or minusthe angular oscillations varying, for example, from 5 to 15, also admitsas compared to the structure of FIG. 1 of enlarged inlet and outletopenings 44, for clockwise rotation, part 44 of FIG. 3 represents thevacuum side, and part 4-5, the pressure side of a pump.

In case the principle of FIG. 3 is to be used to produce a vacuum aswell as pressure, opening 4-4 may be made smaller, preferably simiiar toopening 45.

In the modification shown in FIG. 8, Vane friction is further reduced byproviding, in wall portions or recesses 33 of a rotor 34, rollers 35rotatably mounted on a shaft 36 which in turn is mounted in rotor 34.Rollers d 35 hold therebetween the vanes such as shown in FIG. 8 at 37thereby reducing vane friction to a predetermined and desired extent.

All gaps of course should be held to a minimum size to reduce leakage.

In the modification of FIG. 9, the wall of rotor 2, such as shown in anyof FIGS. 1-8, is conically shaped or tapered outside, as shown at 38, inorder to compensate for the deformation shown in dotted line at 39occurring due to centrifugal force during rotation of the rotor at highspeed.

In another modification such as shown in FIG. 10, casing 1 is providedwith an inner taper such as shown at 40.

If required, both the outer surface of rotor 2 and the inner surface ofcasing 1 may be tapered without departing from the scope of theinvention, as can be easily visualized Without any further illustration.

In FlGS. 1-2, vanes 11, 12, 13, as stated above, are supported withtheir hubs sliding on a fixed shaft 7.

MG. 11 shows a modification in which a shaft of the type shown in KG. 1at 7 is arranged rotatable in the wall of a cover plate such asschematically shown in FIG. 11 at 1.

The vanes, such as shown in FIG. 11 at 46, are rigidly attached to shaft7 which is supported in ball bearings 47 which in turn are supported oncover plate It.

In this way in FIG. 11 the individual friction of the sliding hubs 8, 9,1t supporting vanes 11, 12, 13 in FIGS. l3 is reduced to a singlefriction in the form of ball-bearings 47. Accordingly, assembly issubstantially facilitated.

In order to accommodate the rather large oscillatory movement of therelatively fixed vanes, however, the slots must be made relatively largewhich may be accomplished, for example, as shown in FIGS. 16 and 17. t

In the modification shown diagrammatically in FIG. 12, vanes 48 arerigidly attached to individual hub 49 and rotatable about common shaft50, the outer ends of the vanes having attached rotatably theretoguiding vanes or flaps schematically shown in FIG. 12 at 51, 52, and 53,respectively.

1 he opposite ends of flaps SI, 52, 53 in turn are hingedly attached tothe ends of rotor sectors 54-, 55, 56 forming the rotor of a vane pumpwhich is eccentrically supported and rotated in otherwise well knownmanner.

In this modification, vane friction is further reduced by avoiding anysliding contact of vanes 43 with the rotor.

The perspective view of FIG. 13 explains this type of movement ingreater detail with the vane indicated at 48 and movingcircumferentially in directions 58 in the large gap between sectors 54and 56 of an eccentric rotor.

At the same time, flap 51 is attached by its rotary hinges,schematically indicated at 66 and 59, respectively, to sector 5 -3. andvane 48, respectively, thus assuring the proper guidance of the vanemovement together with reduction of friction.

in the modification of FIGS. 14 and 15, vanes 48 of FIG. 13 are replacedby rods, one of which is shown in FIGS. 14 and 15 at 66 and arrangedmovable in slots schematically indicated at 57 under the guidance offlaps or vanes 63 hingedly attached at both ends to rod 66 and rotor 6?,respectively.

Reduction of dead space is assured by providing around opening 67' abellow member, schematically indicated in PEG. 14 at 7% and permittingfree movement of rod on while effecting a seal between the high andlow-pressure areas on either side of vane 63.

While the embodiments in FIGS. l-l5 assumed vanes with rotationalfreedom, relative to each other, FIGS. 16 and 17 show embodiment Wherethe vanes are rigidly mounted on a shaft. Thus, arrangements must bemade to permit (angular) oscillatory motion relative to the rotor slots.This is accomplished in FIG. 16 by sliding members 75 and in FIG. 17 bytriangular rotating members 80.

In the modification of FIG. 16, a seal is effected by providing in thewalls of the relatively large openings 71 of a rotor 72 longitudinalslots extending in a direction parallel to the rotor axis asschematically indicated in FIG. 16 at 73 and 74-, respectively.

Within these slots 73 and 74 anti-friction members, for example plasticplates, are arranged slidingly, one being schematically shown at 75,having slots 76 which errnit movements of vanes of the type shown inFIG. 16 at 77 relative to rotor 72 in directions indicated by arrows 78and 79, respectively.

At the same time, during these vane movements, slots 71 in rotor 72remain continuously closed thereby preventing leakage.

The modification of FIG. 17 also provides continuous coverage ofrelatively large slots in a rotor such as shown in FIG. 17 at 78.

In this case, slots of the type shown at '79 are continuously covered bytriangular cover members 80 made of low-friction metal or plastic (orprovided if necessary at the friction points with low-friction inserts)and supported on shaft 81 of rotor 78'.

It is apparent that in this case vanes must extend at their points 82outside of rotor 78 over the entire length of gap 79' while their innerportion or holding arm 83 must be cut out as shown in FIG. 17 at 83 whensupported on its respective shaft so as to clear the triangular covermembers 80 and shaft 81.

The invention is not limited to the particular shape of vanes,supporting members, cover members, rotors, rotor parts, stators andstator parts, nor to the arrangements or connections shown or describedbut may be applied in any form or manner whatsoever without departingfrom the scope or" this disclosure.

1 claim:

1. A rotary pump, comprising an outer casing having a longitudinal axisand having an inner space with transverse end walls and a peripheralwall having at least a part-cylindrical portion, a shaft, means mountingsaid shaft rotatably in said casing with said shaft extending axially,the axes of said shaft and said part-cylindrical portion beingco-incident, a cylindrical rotor, means mounting said rotor in saidcasing so that its axis is ottset with respect to and parallel to saidlongitudinal axis, said shaft extending through said rotor, said rotorhaving axial slots extending in the direction of length thereof andequally circumferentially spaced, an elastomer hub fixedly mounted onsaid shaft and of generally cylindrical shape, said hub having unitary,equally circumferentially spaced, integral, circumferentially flexibleand resilient projections extending radially therefrom in respectivegeneral correspondence with respective rotor slots and located radiallyinwardly of said rotor, rigid vanes respectively secured to therespective hub projections, said vanes extending generally radially fromsaid hub and also extending longitudinally, said vanes being of lengthcorresponding to the axial length of said rotor slots, said hub and saidprojections being of generally the same length as said vanes, said vanesrespectively extending slidably through the respective rotor slots, thetips of said vanes being located in a cylinder of revolution whose axisis said longitudinal axis, said part-cylindrical peripheral wall portionhaving a radius such as to receive the tips of the rotating vanes inclose, generally uniformly spaced relationship to said part-cylindricalperipheral wall portion.

2. Rotary pump according to claim 1, said vanes being embedded in saidhub projections.

3. A rotary pump comprising an outer casing having a longitudinal axisand having an inner space with transverse end walls and a peripheralwall having at least a part-cylindrical portion, a shaft, means mountingsaid shaft rotatably in said casing with said shaft extending axially,the axes of said shaft and said part-cylindrical portion beingco-incident, a cylindrical rotor, means mounting said rotor in saidcasing so that its axis is offset with respect to and parallel to saidlongitudinal axis, said shaft extending through said rotor, said rotorhaving axial slots extending in the direction of length thereof andequally circumferentially spaced, an elastomer hub fixedly mounted onsaid shaft and of generally cylindrical shape, said hub having unitary,equally circumferentially spaced, integral, circumferentially flexibleand resilient projections extending radially therefrom in respectivegeneral correspondence with respective rotor slot and located radiallyinwardly of said rotor, rigid vanes respectively secured to therespective hub projections, said vanes extending generally radially fromsaid hub and also extending longitudinally, said vanes being of lengthcorresponding to the axial length of said rotor slots, said hub and saidprojections being of generally the same length as said vanes, said vanesrespectively extending slidably through the respective rotor slots, saidrotor having sealing means on each longitudinal edge of each slotengaging frictionally and sealingly against the opposite faces of thevane in said slot, the tips of said vanes being located in a cylinder ofrevolution whose axis is said longitudinal axis, said part-cylindricalperipheral Wall portion having a radius such as to receive the tips ofthe rotating vanes in close, generally uniformly spaced relationship tosaid part-cylindrical peripheral wall portion.

4. Rotary pump according to claim 3, said vanes being embedded in saidhub projections.

References (Cited in the file of this patent UNITED STATES PATENTS891,372 Reichhelm June 23, 1908 1,007,933 English Nov. 7, 1911 1,045,754Smith Nov. 26, 1912 1,053,321 Schrock Feb. 18, 1913 1,221,333 KillmanApr. 3, 1917 1,227,968 Silvestri May 29, 1917 1,535,275 Westin Apr. 28,1925 1,607,383 Aurand Nov. 16, 1926 1,716,901 Rochford June 11, 19291,852,503 Cambell Apr, 5, 1932 2,071,799 Mobille Feb. 23, 1937 2,189,356Briggs Feb. 6, 1940 2,233,017 Lambin Feb. 25, 1941 2,387,629 WaseigeOct. 23, 1945 2,470,656 Shorrock May 17, 1949 2,814,255 Lorenzetti Nov.26, 1957 FOREIGN PATENTS 2,328 Great Britain of 1868 882 Great Britainof 1880 27,906 Great Britain of 1902 128,677 Great Britain July 3, 1919204,852 Germany Dec. 5, 1908 1,029,522 Germany May 8, 1958 180,761Switzerland Feb. 1, 1936 1,063,685 France Dec. 16, 1953

1. A ROTARY PUMP, COMPRISING AN OUTER CASING HAVING A LONGITUDINAL AXISAND HAVING AN INNER SPACE WITH TRANSVERSE END WALLS AND A PERIPHERALWALL HAVING AT LEAST A PART-CYLINDRICAL PORTION, A SHAFT MEANS MOUNTINGSAID SHAFT ROTATABLY IN SAID CASING WITH SAID SHAFT EXTENDING AXIALLY,THE AXES OF SAID SHAFT AND SAID PART-CYLINDRICAL PORTION BEINGCO-INCIDENT, A CYLINDRICAL ROTOR, MEANS MOUNTING SAID ROTOR IN SAIDCASING SO THAT ITS AXIS IS OFFSET WITH RESPECT TO AND PARALLEL TO SAIDLONGITUDINAL AXIS, SAID SHAFT EXTENDING THROUGH SAID ROTOR, SAID ROTORHAVING AXIAL SLOTS EXTENDING IN THE DIRECTION OF LENGTH THEREOF ANDEQUALLY CIRCUMFERENTIALLY SPACED, AN ELASTOMER HUB FIXEDLY MOUNTED ONSAID SHAFT AND OF GENERALLY CYLINDRICAL SHAPE, SAID HUB HAVING UNITARY,EQUALLY CIRCUMFERENTIALY SPACED, INTEGRAL, CIRCUMFERENTIALLY FLEXIBLEAND RESILIENT PROJECTIONS EXTENDING RADIALLY THEREFROM IN RESPECTIVEGENERAL CORRESPONDENCE WITH RESPECTIVE ROTOR SLOTS AND LOCATED RADIALLYINWARDLY OF SAID ROTOR, RIGID VANES RESPECTIVELY SECURED TO THERESPECTIVE HUB PROJECTIONS, SAID VANES EXTENDING GENERALLY RADIALLY FROMSAID HUB AND ALSO EXTENDING LONGITUDINALLY, SAID VANES BEING OF LENGTHCORRESPONDING TO THE AXIAL LENGTH OF SAID ROTOR SLOTS, SAID HUB AND SAIDPROJECTIONS BEING OF GENERALLY THE SAME LENGTH AS SAID VANES, SAID VANESRESPECTIVELY EXTENDING SLIDABLY THROUGH THE RESPECTIVE ROTOR SLOTS, THETIPS OF SAID VANES BEING LOCATED IN A CYLINDER OF REVOLUTION WHOSE AXISIS SAID LONGITUDINAL AXIS, SAID PART-CYLINDRICAL PERIPHERAL WALL PORTIONHAVING A RADIUS SUCH AS TO RECEIVE THE TIPS OF THE ROTATING VANES INCLOSE, GENERALLY UNIFORMLY SPACED RELATIONSHIP TO SAID PART-CYLINDRICALPERIPHERAL WALL PORTION.